We elected to stop this study due to our inability to recruit suitable subjects.

2. Purpose of the Study -

1. To determine the feasibility of Clevidipine use for rapidly achieving and maintaining individually specified patient BP target ranges in the pre and postoperative periods of aortic aneurysm and dissection management.

2. To determine the safety of Clevidipine use in the pre and postoperative periods of aneurysm and dissection management

3. Background & Significance - Surgical treatments for persons with aortic root/arch dissection or aneurysm have significantly improved survival. However, critical in management of these patients is precise control of blood pressure (BP). With increasing BP, both acute and chronic, the risk of fatal and nonfatal vascular complications is imminent. Similarly, with excessive lowering of arterial pressures, cerebral, spinal cord, cardiac, and renal ischemic hypoperfusion is also noteworthy. Typically, the target systolic blood pressure range for these patients is 100-120 mmHg.

   Several different classes of vasoactive agents are in current use to acutely manage BP but none possess the optimal profile of an ideal vasodilator. Notable limitations include inadequate potency, slow onset and offset of action, multiple receptor function, safety concerns and, importantly, restricted/ineffective titration, which results in clinically significant hemodynamic and cardiovascular perturbations.

   Recently, the ultra short-acting intravenous dihydropyridine calcium-channel blocker clevidipine (Cleviprex, The Medicines Company) was approved for management of BP in critical care settings.

   Clevidipine's pharmacology lends itself to acute management of BP in a broad critical care setting in both surgical and nonsurgical patients. In the current study, the investigators propose to further characterize the hemodynamic effect of CLV in the pre and post-operative management of BP in patients with aortic aneurysm/dissection.

4. Design & Procedures Eligible patients will be approached to participate in the study by the Intensive Care Unit (ICU) attending and/or by a cardiothoracic surgical/anesthesiology fellow or a cardiac research nurse. All aspects of clinical management and monitoring will be according to standard practice that includes:

   • ECG
   • Oxymetry
   • Temperature
   • Invasive arterial blood pressure
   • Recording of routine laboratory results
   • Imaging studies including CT/MRI (A)/ Echocardiography
   • Pulmonary artery catheter (postoperative patients)
   • Mechanical ventilation (postoperative patients)
   • According to established protocol for acute intravenous management of arterial blood pressure in these patients, an upper and lower threshold of systolic blood pressure will be prescribed by the attending physician (the range being (100 mmHg -120 mm Hg SBP).

Hemodynamic data will be collected continuously via a bedside laptop as well as pertinent clinical data and information about efficacy and safety will be recorded.

• Subjective evaluation of efficacy of CLV (questionnaire format to be completed by the critical care team)

Inclusion Criteria:

1. Adult patients (age 18-80 years)
2. Able to provide written consent
3. Type I and Type II (Type A) aortic dissection or unstable chronic aortic aneurysm
4. Patients expected to be admitted to ICU following aortic surgery for either dissection or aneurysm requiring acute management of elevated systolic blood pressure (consent obtained preoperatively)

Exclusion Criteria:

1. Unstable emergent dissections
2. Evidence of end-organ dysfunction (ischemia of spinal cord, bowel, myocardium or renal)
3. Active bleeding
4. Allergies to soybeans, soy products, eggs, or egg products; defective lipid metabolism such as pathologic hyperlipemia, lipoid nephrosis, or acute pancreatitis
5. Women who are pregnant
6. Female subjects of child bearing potential must have a blood serum pregnancy test performed prior to participating in this study and the results must be negative.